Re: [PATCH 1/5] cpumask: update irq_desc to use cpumask_var_t

[Yinghai Lu <yinghai@kernel.org>]

Mike Travis wrote:
> Yinghai Lu wrote:
> ...
>>> Or am I missing your point?
>> static void init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
>>                  struct irq_desc *desc, int cpu)
>> {
>>         memcpy(desc, old_desc, sizeof(struct irq_desc));
>>
>>
>> will overwrite new_desc->affinity and pending_mask
>>
>> YH
> 
> Yup, apparently I was missing your point (banging on head once more).
> 
> Thanks for spotting this!
> 
> Ingo - what's the state of tip/cpus4096?  Shall I push this as an
> append patch, or redo the original so bisectability works.
> 
> Also, Yinghai - would you know of a straight forward way to test
> the irq migration?   I have taken cpus offline and back online
> but wasn't sure if any irq's were being moved off of cpu 0 which
> cannot be taken offline.

use echo "mask" > /proc/irq/xxx/smp_affinity to change affinity

and check /proc/interrupts and in /sys/log/messages i will said allocate new irq desc on some other node/cpu.

YH